Electrical systems, and electrically powered mechanisms, often require switches that are exposed to severe weather conditions. In such an environment, snow, ice and the like can, with time, completely encrust the switch. If the switch is not designed to properly operate when so encrusted, its function and usefullness will be impaired or destoryed. Few switches have met the test of such severe conditions. No simple, economical, readily servicable switch has proven satisfactory.
As an example of such a switch and system, ski lifts require by law some form of controller adjacent to each tower over which the lift enable cable passes, and at various positions about the upper and lower ends of the ski lift run. These controllers must be positioned to sense any movement of the ski lift cable beyond a predetermined point, such as would occur if the cable becomes derailed, and other conditions adjacent the ends of the ski lift, any one of which will cause the controller to stop operation of the lift immediately. Should this occur, it is required that the controller manually be reset by the ski lift operator, the manual resetting operation giving the operator an opportunity to inspect the problem area to determine and correct the cause of the malfunction.
As an example, one type of controller that has been employed in ski lift systems is a simple printed circuit board positioned to be physically broken by a malfunction. Of course, this physical destruction of the controller by a malfunction is expensive. The operator must replace the broken circuit board and make good electrical contact to reconnect and complete this controller system. When it is cold, snowing, or very windy, it is quite difficult to do this high on a ski lift tower. The tendency of the operator, instead of facing such a chore, is to simply bypass the switch with a short rendering the controller ineffective but at least re-establishing the operation of the ski lift.